scholarly journals CALCULATION OF THE Bc LEPTONIC DECAY CONSTANT USING THE SHIFTED N-EXPANSION METHOD

2006 ◽  
Vol 21 (32) ◽  
pp. 6699-6714 ◽  
Author(s):  
SAMEER M. IKHDAIR ◽  
RAMAZAN SEVER

We give a review and present a comprehensive calculation for the leptonic constant fBc of the low-lying pseudoscalar and vector states of Bc-meson in the framework of static and QCD-motivated nonrelativistic potential models taking into account the one-loop and two-loop QCD corrections in the short distance coefficient that governs the leptonic constant of Bc quarkonium system. Further, we use the scaling relation to predict the leptonic constant of the nS-states of the [Formula: see text] system. Our results are compared with other models to gauge the reliability of the predictions and point out differences.

2012 ◽  
Vol 16 (5) ◽  
pp. 1519-1523
Author(s):  
Pei-Feng Lin ◽  
Di-Chong Wu ◽  
Ze-Fei Zhu

Ultra-fine particle coagulation by Brownian motion at high concentration in planar jet flow is simulated. A Taylor-Series Expansion Method of Moments is employed to solve the particle general dynamic equation. The volume fraction gets high value, very closes to that at the nozzle exit. As the vortex pairing develops, the high volume fraction region rolls out and mixes with the low value region. The enhancement factor given by Trzeciak et al. will be less than one at some specific outer positions, which seems to be less accurate than the one given by Heine et al.


2012 ◽  
Vol 16 (5) ◽  
pp. 1331-1338 ◽  
Author(s):  
Wenxi Wang ◽  
Qing He ◽  
Nian Chen ◽  
Mingliang Xie

In the study a simple model of coagulation for nanoparticles is developed to study the effect of diffusion on the particle coagulation in the one-dimensional domain using the Taylor-series expansion method of moments. The distributions of number concentration, mass concentration, and particle average volume induced by coagulation and diffusion are obtained.


Author(s):  
Peter Mitchell

Over 50,000 years ago a Neanderthal hunter approached a wild ass on the plains of northeastern Syria. Taking aim from the right as the animal nervously assessed the threat, he launched his stone-tipped spear into its neck, penetrating the third cervical vertebra and paralyzing it immediately. Butchered at the kill site, this bone and most of the rest of the animal were taken back to the hunter’s camp at Umm el Tlel, a short distance away. Closely modelled on archaeological observations of that vertebra and the Levallois stone point still embedded within it, this incident helps define the framework for this chapter. At the start of the period it covers, human interactions with the donkey’s ancestors were purely a matter of hunting wild prey, but by its end the donkey had been transformed into a domesticated animal. Chapter 2 thus looks at how this process came about, where it did so, and what the evolutionary history of the donkey’s forebears had been until that point. Donkeys and the wild asses that are their closest relatives form part of the equid family to which zebras and horses also belong. Collectively, equids, like rhinoceroses and tapirs, fall within the Perissodactyla, the odd-toed division of hoofed mammals or ungulates. Though this might suggest a close connection with the much larger order known as the Artiodactyla, the even-toed antelopes (including deer, cattle, sheep, and goats), their superficial resemblances may actually reflect evolutionary convergence; some genetic studies hint that perissodactyls are more closely related to carnivores. Like tapirs and rhinoceroses, the earliest equids had three toes, not the one that has characterized them for the past 40 million years. That single toe, the third, now bears all their weight in the form of a single, enlarged hoof with the adjacent toes reduced to mere splints. This switch, and the associated elongation of the third (or central) metapodial linking the toe to the wrist or ankle, is one of the key evolutionary transformations through which equids have passed. A second involves diet since the earliest perissodactyls were all browsers, not grazers like the equids of today.


2013 ◽  
Vol 110 (17) ◽  
Author(s):  
A. Bazavov ◽  
C. Bernard ◽  
C. DeTar ◽  
J. Foley ◽  
W. Freeman ◽  
...  

1963 ◽  
Vol 41 (11) ◽  
pp. 1911-1923 ◽  
Author(s):  
E. R. Kanasewich ◽  
J. C. Savage

It has long been recognized that Dirac's principle might imply that the rate of β decay would vary with the age of the universe. If so, the radioactive ages of meteorites and terrestrial rocks as indicated on the one hand by α decay and on the other by β decay should differ. However, the comparison of these ages is complicated by a large uncertainty in the decay constant for Rb87. Thus the age data must be analyzed to determine the decay constant most compatible with the particular theory of β decay which is used. Using this best decay constant for each theory, we find that the data are more consistent with a β decay rate independent of the age of the universe than with the dependence implied by the Dirac principle.


2016 ◽  
Vol 30 (28n29) ◽  
pp. 1640013 ◽  
Author(s):  
Bang-Xing Guo ◽  
Ji Lin

We study the Panilevé property of the coupled equations describing the interaction of few-cycle-pulse with nonlinear medium. And we use the consistent tanh expansion (CTE) method to search for exact interaction soliton solutions of the coupled equations. Many interaction solutions are obtained, such as the one kink-one periodic wave interaction solution, one kink-two periodic waves interaction solution, one kink-one dipole soliton interaction solution, one kink-two dipole solitons interaction solution, and one kink-soliton-one periodic wave interaction solution. We also obtain the kink–kink interaction by using Painlevé truncated expansion method.


2008 ◽  
Vol 17 (04) ◽  
pp. 669-691 ◽  
Author(s):  
SAMEER M. IKHDAIR ◽  
RAMAZAN SEVER

In the framework of static and QCD-motivated model potentials for heavy quarkonium, we present a further comprehensive calculation of the mass spectrum of [Formula: see text] system and its ground state spin-dependent splittings in the context of the shifted l-expansion technique. We also predict the leptonic constant fBc of the lightest pseudoscalar Bc, and [Formula: see text] of the vector [Formula: see text] states taking into account the one-loop and two-loop QCD corrections. Furthermore, we use the scaling relation to predict the leptonic constant of the nS-states of the [Formula: see text] system. Our predicted results are generally in high agreement with some earlier numerical methods. The parameters of each potential are adjusted to obtain best agreement with the experimental spin-averaged data (SAD).


2000 ◽  
Vol 61 (7) ◽  
Author(s):  
K-I. Ishikawa ◽  
N. Yamada ◽  
S. Aoki ◽  
M. Fukugita ◽  
S. Hashimoto ◽  
...  

1993 ◽  
Vol 298 (1-2) ◽  
pp. 190-194 ◽  
Author(s):  
C.A. Dominguez ◽  
K. Schilcher ◽  
Y.L. Wu

2020 ◽  
Vol 10 (8) ◽  
pp. 2843
Author(s):  
Qi Qin ◽  
Meiping Sheng ◽  
Zhiwei Guo

The low-frequency vibration and radiation performance of a locally resonant (LR) plate with periodic multiple resonators is studied in this paper, with both infinite and finite structure properties examined. For the finite cases, taking the LR plate attached with two periodic arrays of resonators as an example, the forced vibration response and the radiation efficiency are theoretically derived by adopting a general model with elastic boundary conditions. Through a comparison with the band structures calculated by the plane-wave-expansion method, it shows that the band gaps in the infinite LR plate are in good agreement with the vibration-attenuation bands in the finite LR plate, no matter what boundary conditions are applied to the latter. In contrast to the vibration reduction in the band gaps, the radiation efficiency of the finite LR plate is sharply increased in the band-gap frequency ranges. Furthermore, the acoustic power radiated from the finite LR plate can be seriously affected by its boundary conditions. For the LR plate with greater constraints, the acoustic power is reduced in the band-gap frequency ranges, while that from the one with fully free boundary conditions is increased. When further considering the damping loss factors of the resonators, the attenuation performance can be improved for both the vibration and radiation of the LR plate.


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